This is a question for those who still hold a supernatural view of the bible.
It would seem to be certain that the gospel of Mark was the first to be written, and that Matthew and Luke copied large parts of Mark when compiling their gospels.
From a theological perspective the most important event in the story - the heart of the gospel or "good news" is the resurrection of Jesus. It was this event and its implications that the disciples proclaimed.
The way that Mark reports the resurrection is puzzling.
When the Sabbath was over, Mary Magdalene, Mary the mother of James, and Salome bought spices so that they might go to anoint Jesus’ body. 2 Very early on the first day of the week, just after sunrise, they were on their way to the tomb 3 and they asked each other, “Who will roll the stone away from the entrance of the tomb?”
4 But when they looked up, they saw that the stone, which was very large, had been rolled away. 5 As they entered the tomb, they saw a young man dressed in a white robe sitting on the right side, and they were alarmed.
6 “Don’t be alarmed,” he said. “You are looking for Jesus the Nazarene, who was crucified. He has risen! He is not here. See the place where they laid him. 7 But go, tell his disciples and Peter, ‘He is going ahead of you into Galilee. There you will see him, just as he told you.’”
8 Trembling and bewildered, the women went out and fled from the tomb. They said nothing to anyone, because they were afraid.
The verses that follow in many modern bibles are certainly not original. The oldest manuscripts finish with this strange cliff-hanger. The only witnesses to empty tomb tell nobody about what they have seen and heard.
The answer would seem to be that the remainder of Mark's gospel has simply got lost. If Mark's gospel was writen in a codex format it is likely that the last page was lost or damaged before it was copied.
Does it not seem strange that if the bible was inspired of god that the most important part of the earliest gospel was not preserved?
Why did this not worry me when I was a JW or later as a christian?